So was it the Flat-harp that was creating all these visions? or was it her inner conflict about joining the league...I wonder where she heard that passage from? "This instrument will be the key to unlocking the world. It will speak for you more truly than a voice ever could. Nothing else – not us, them, or any magic in this world will ever own you again." ...Please tell me your working on a novel to tie all these things together.

To be honest I was a little disappointed in this one, while I understand that she is mute, given that the judgments are done within the mind it was possibly your one chance of giving her a limited voice. Because although she is mute, within her mind she would still hear her own thoughts.
This Judgment though didn't provide very much, we're not sure of much of her background or reasoning for joining the league, we're given a hint that possibly she accidentally slew her adoptive mother or that her instrument did it of it's own designs. Honestly I would've liked just a little more detail as to her motivation instead of a vague impression and I think we actually got more info about her in the JoJ piece about her.
Just my 2 cents.